Film forming apparatus and a barrier film producing method

Abstract

A film forming apparatus is used in a semiconductor manufacturing process and a method for producing a barrier film is used for a semiconductor. When a metallic gas and a reactive gas are alternatively flown, a back-flow preventing gas and an auxiliary gas are flown, the reactive gas and the auxiliary gas are moved with the flow of the back-flow preventing gas, and radicals are produced by being in contact with them to a catalytic material. Since the metallic material gas is not in contact with the catalytic material, the catalytic material is not degraded. A shower plate may be disposed between a radical producing chamber and a reaction chamber, so that the radicals are fed into the reaction chamber through holes. Thus, a barrier film having low resistance and excellent coverage is formed.

Description

RELATED APPLICATIONS[0001]This application is a division of U.S. patent application Ser. No. 12 / 251,793, filed Oct. 15, 2008, which application is a continuation of International Application No. PCT / JP2007 / 058311 filed Apr. 17, 2007, which claims priority of Japanese Patent Document No. 2006-114789, filed on Apr. 18, 2006, the entire contents of which are incorporated herein by reference.BACKGROUND[0002]The present invention generally relates to a film forming apparatus for use in a semiconductor-producing process and a method for producing a barrier film to be used in a semiconductor.[0003]In the process for producing Cu wirings to be used in semiconductor devices, the film forming temperature is limited to 300 degree Celsius or less. This is the reason why when the film forming temperature is not less than 300 degrees Celsius, a phenomenon so-called stress migration (SM) occurs to the Cu wiring so that the reliability of the Cu wirings is conspicuously deteriorated.[0004]In a conv...

AI Technical Summary

Benefits of technology

[0011]An object of the present invention is to provide a technique of forming a barrier film having a low resistance and excellent coverage performance and containing no impurities at a low temperature (300 degrees Celsius or less).

[0025]The barrier film obtained by the present invention does not contain the impurities and has extremely good adhesion to Cu so that the film can undergo a CMP step without being peeled. In addition, the barrier film having a specific resistance of around dozens μΩ cm is obtained, while the specific resistance of the barrier film in the prior art is a few hundred to several thousand μΩ cm. Thus, a via resistance can be reduced, and a great effect is obtained for speeding up an operation speed of a device.

Problems solved by technology

This is the reason why when the film forming temperature is not less than 300 degrees Celsius, a phenomenon so-called stress migration (SM) occurs to the Cu wiring so that the reliability of the Cu wirings is conspicuously deteriorated.

However, since the barrier metal obtained by this method includes many impurities (such as, C and O), only film having high specific resistance (a few hundred to several thousand μΩ cm) can be obtained.

Further, since many impurities are contained, there is a problem in that adhesion between the barrier film and a Cu film as an upper layer is low.

When the adhesion is low in a Cu process, the film is peeled in a CMP step, thereby resulting in a fatal defect.

However, there is a problem in that the gases of the inorganic metallic materials have high pyrolysis temperatures of 400 degrees Celsius or more.

Such barrier film has poor coverage.

However, although the above reactions occur at 400 degrees Celsius or more, the reaction does not almost proceed at 300 degrees Celsius or less.

However, there is a problem in that a reaction product is deposited on a surface of a catalytic material, and the catalytic material must be frequently cleaned.

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